Search

Lithium-ion battery (LIB) has gained significant recognition for the power cell market owing to its impressive energy density and appealing cost benefit. Among various cathodes, a high-voltage cobalt-poor lithium nickel manganese cobalt oxide cathode (Co-poor NCM cathode) has been considered as a promising strategy to enhance its energy density. Despite these advantages, high-voltage Co-poor NCM cathode-graphite full battery usually suffers from poor rate performance. However, fast charging has been a key indicator for widespread application of power batteries. Although many efforts have been made to improve the charging performance of fresh batteries, few works investigate the charging ability during calendar aging and cycling aging of high-voltage Co-poor NCM cathode-graphite full battery. In this work, we found that the charging ability becomes worse during calendar aging and cycling aging. Results showed that the increasing charge transfer resistance from the cathode is the major obstacle to achieving fast charging during the aging process. To address the problem, high-voltage Al2O3-coated Co-poor NCM cathode successfully prepared via a simple atomic layer deposition (ALD) method has been developed to reduce the decay of charging performance during calendar aging and cycling aging. Al2O3-coated NCM cathode can effectively reduce the growth rate of the resistance of cathode, which is benefiting from the conversion of Al2O3into LiAlO2with high ionic conductivity and the restriction formation of rock salt phase. Benefiting from the decreased charge transfer resistance of the NCM cathode, the mismatch of the lithium-ion reaction kinetics is well alleviated, thus effectively reducing the polarization under fast charging. As a result, Al2O3-coated NCM cathode-graphite full battery shows the slow deterioration of charging performance during the aging process. This work provides a promising strategy for constructing fast-charging batteries during calendar aging and cycling aging.

Superionic halides have attracted widespread attention as solid electrolytes due to their excellent ionic conductivity, soft texture, and stability toward high-voltage electrode materials. Among them, Li3InCl6has aroused interest since it can be easily synthesized in water or ethanol. However, investigations into the influence of solvents on both the crystal structure and properties remain unexplored. In this work, Li3InCl6is synthesized by three different solvents: water, ethanol, and water–ethanol mixture, and the difference in properties has been studied. The results show that the product obtained by the ethanol solvent demonstrates the largest unit cell parameters with more vacancies, which tend to crystallize on the (131) plane and provide the 3D isotropic network migration for lithium-ions. Thus, it exhibits the highest ionic conductivity (1.06 mS cm–1) at room temperature and the lowest binding energy (0.272 eV). The assembled all-solid-state lithium metal batteries (ASSLMBs) employing Li3InCl6electrolytes demonstrate a high initial discharge capacity of 153.9 mA h g–1at 0.1 C (1 C = 170 mA h g–1) and the reversible capacity retention rate can reach 82.83% after 50 cycles. This work studies the difference in ionic conductivity between Li3InCl6electrolytes synthesized by different solvents, which can provide a reference for the future synthesis of halide electrolytes and enable their practical application in halide-based ASSLMBs with a high energy density.

Reactive metal–support interaction (RMSI) is an emerging way to regulate the catalytic performance for supported metal catalysts. However, the induction of RMSI by the thermal reduction is often accompanied by the encapsulation effect on metals, which limits the mechanism research and applications of RMSI. In this work, a gradient orbital coupling construction strategy was successfully developed to induce RMSI in Pt-carbide system without a reductant, leading to the formation of L12-PtxM-MCy(M = Ti, Zr, Hf, V, Nb, Ta, Cr, Mo, and W) intermetallic electrocatalysts. Density functional theory (DFT) calculations suggest that the gradient coupling of the d(M)-2p(C)-5d(Pt) orbital would induce the electron transfer from M to C covalent bonds to Pt NPs, which facilitates the formation of C vacancy (Cv) and the subsequent M migration (occurrence of RMSI). Moreover, the good correlation between the formation energy of Cvand the onset temperature of RMSI in Pt-MCxsystems proves the key role of nonmetallic atomic vacancy formation for inducing RMSI. The developed L12-Pt3Ti-TiC catalyst exhibits excellent acidic methanol oxidation reaction activity, with mass activity of 2.36 A mgPt–1in half-cell and a peak power density of 187.9 mW mgPt–1in a direct methanol fuel cell, which is one of the best catalysts ever reported. DFT calculations reveal that L12-Pt3Ti-TiC favorably weakens *CO absorption compared to Pt-TiC due to the change of the absorption site from Pt to Ti, which accounts for the enhanced MOR performance.

The solid-state battery with a lithium metal anode is a promising candidate for next-generation batteries with improved energy density and safety. However, the current polymer electrolytes still cannot fulfill the demands of solid-state batteries. In this work, we propose a “5H” poly(ethylene oxide) (PEO) electrolyte via introducing a multifunctional additive of tris(pentafluorophenyl)borane (TPFPB) for high-performance lithium metal batteries. The addition of TPFPB improves the ionic conductivity from 6.08 × 10–5to 1.54 × 10–4S cm–1via reducing the crystallinity of the PEO electrolyte and enhances the lithium-ion transference number from 0.19 to 0.53 via anion trapping due to its Lewis acid nature. Furthermore, the fluorine and boron segments from TPFPB can optimize the composition of the solid–electrolyte interphase and cathode–electrolyte interphase, providing a high electrochemical stability window over 4.6 V of the PEO electrolyte along with significantly improved interface stability. At last, TPFPB can ensure improved safety through a self-extinguishing effect. As a result, the “5H” electrolyte enables the Li/Li symmetric cells to achieve a stable cycle over 2200 h at the current density of 0.2 mA cm–2with a capacity of 0.2 mA h cm–2; the LiFePO4/Li full cells with a high LFP loading of 8 mg cm–2exhibits decay-free capacity of 140 mA h g–1(99% capacity retention) after 100 cycles; and the NCM811/Li cells exhibit a high capacity of 160 mA h g–1after 50 cycles at 0.5 C. This work presents an innovative approach to utilizing a “5H” electrolyte for high-performance solid-state lithium batteries.

The cobalt-free layered oxide cathode of LiNi0.65Mn0.35O2is promising for high-energy-density lithium-ion batteries (LIBs). However, under high-voltage conditions, severe side reactions between the Co-free cathode and electrolyte, as well as grain boundary cracks and pulverization of particles, hinder its practical applications. Herein, an electrolyte regulation strategy is proposed by adding fluoroethylene carbonate (FEC) and LiPO2F2as electrolyte additives in carbonate-based electrolytes to address the above issues. As a result, a homogeneous and dense organic–inorganic hybrid cathode electrolyte interface (CEI) film is formed on the cathode surface. The CEI film consists of C-F, LiF, Li2CO3, and LixPOyFzspecies, which is proven to be highly conductive and effective in suppressing structure damage and alleviating the interfacial reactions between the cathode and electrolyte. With such a CEI film, the interfacial stability of the Co-free cathode and the high-voltage cycling performance of Li||LiNi0.65Mn0.35O2are greatly improved. A reversible capacity of 155.1 mAh g–1and a capacity retention of 81.3% over 150 cycles are attained at a 4.8 V charge cutoff voltage with the tamed electrolyte, whereas the cell without the additives only retains 76.1% capacity retention. Therefore, our work demonstrates the synergistic effect of FEC and LiPO2F2in stabilizing the interface of Co-free cathode materials and provides an alternative strategy for the electrolyte design of high-voltage LIBs.

As the classic cathode material, lithium cobalt oxide (LiCoO2, LCO) suffers from severe structural and interfacial degradation at voltage >4.5 V, which induces fast capacity decay of the cells. Herein, we adopt a simple and effective method, doping aluminum (Al) cations in precursors, to improve the structural stability of LCO and systematically investigate the effect of Al doping on the electrochemical performances. Doping in precursors rather than bulk particles is beneficial to realize uniform Al ions distribution. Even at 4.5 V charging voltage, the LCO/graphite pouch cells with high Al doping levels (8500 ppm) deliver initial and reversible discharge capacities of 386 and 369 mAh after 500 cycles, respectively. The capacity retention is as high as 95.5%. When the cutoff voltage reaches 4.55 V, the pouch cell maintains 79.0% of the first-cycle discharge capacity after 500 cycles. With optimized electrolyte, the pouch cell realizes 87.3% of the initial discharge capacity after 500 cycles at 45 °C. Moreover, the thermal safety performance of the pouch cells with Al doping is promising. Our work displays an excellent inspiration for developing high-voltage, long-cycle, and safe LCO cathode for commercial lithium-ion batteries.

Surface polarization under harsh electrochemical environments usually puts catalysts in a thermodynamically unstable state, which strictly hampers the thermodynamic stability of Pt-based catalysts in high-performance fuel cells. Here, we report a strategy by introducing electron buffers (variable-valence metals, M = Ti, V, Cr, and Nb) into intermetallic Pt alloy nanoparticle catalysts to suppress the surface polarization of Pt shells using the structurally ordered L10-M-PtFe as a proof of concept. Operando X-ray absorption spectra analysis suggests that with the potential increase, electron buffers, especially Cr, could facilitate an electron flow to form a electron-enriched Pt shell and thus weaken the surface polarization and tensile Pt strain. The best-performing L10-Cr-PtFe/C catalyst delivers superb oxygen reduction reaction (ORR) activity (mass activity = 1.41/1.02 A mgPt–1at 0.9 V, rated power density = 14.0/9.2 W mgPt–1in H2-air under a total Pt loading of 0.075/0.125 mgPtcm–2, respectively) and stability (20 mV voltage loss at 0.8 A cm–2after 60,000 cycles of accelerated durability test) in a fuel cell cathode, representing one of the best reported ORR catalysts. Density functional theory calculations reveal that the optimized surface strain by introducing Cr on L10-PtFe/C accounts for the enhanced ORR activity, and the durability enhancement stems from the charge transfer contribution of Cr to the Pt shells and the increased kinetic energy barrier for Pt dissolution/Fe diffusion.

O3-type layered oxide cathodes are promising for practical sodium-ion batteries (SIBs) owing to their high theoretical capacity, facile synthesis, and sufficient Na+storage. However, they face challenges such as rapid capacity loss and poor cycling stability, mainly attributed to irreversible phase transitions. To address these challenges, a novel cathode material, Li/Sn co-substituted O3-Na0.95Li0.07Sn0.01Ni0.22Fe0.2Mn0.5O2(LSNFM), has been designed by regulating the electronic structure, in which Li+activates more redox reactions of Ni2+/3+and Fe3+/4+above 2.5 V and suppresses the redox reactivity of Mn3+/4+below 2.5 V, while Sn4+can prevent the charge delocalization in the transition metal layer, contributing to structural stability. Due to this synergistic effect, the as-prepared LSNFM electrode with high structural reversibility displays a 27.2% capacity increase contributed by the high-voltage transition metal ion redox activity and exhibits excellent long-term cycling stability, an 84.0% capacity retention after 500 cycles at 1 C and an 84.7% capacity retention after 2000 cycles at 5 C. The fundamental mechanism is fully investigated using systematic in situ/ex situcharacterization techniques and density functional theory computations. This work provides a paradigm for designing long-term cycle life cathode materials by synergistically regulating the electronic structure in practical SIBs.

Structurally ordered L10-PtM (M = Fe, Co, Ni and so on) intermetallic nanocrystals, benefiting from the chemically ordered structure and higher stability, are one of the best electrocatalysts used for fuel cells. However, their practical development is greatly plagued by the challenge that the high-temperature (>600 °C) annealing treatment necessary for realizing the ordered structure usually leads to severe particle sintering, morphology change and low ordering degree, which makes it very difficult for the gram-scale preparation of desirable PtM intermetallic nanocrystals with high Pt content for practical fuel cell applications. Here we report a new concept involving the low-melting-point-metal (M′ = Sn, Ga, In)-induced bond strength weakening strategy to reduce Eaand promote the ordering process of PtM (M = Ni, Co, Fe, Cu and Zn) alloy catalysts for a higher ordering degree. We demonstrate that the introduction of M′ can reduce the ordering temperature to extremely low temperatures (≤450 °C) and thus enable the preparation of high-Pt-content (≥40 wt%) L10-Pt-M-M′ intermetallic nanocrystals as well as ten-gram-scale production. X-ray spectroscopy studies, in situ electron microscopy and theoretical calculations reveal the fundamental mechanism of the Sn-facilitated ordering process at low temperatures, which involves weakened bond strength and consequently reduced Eavia Sn doping, the formation and fast diffusion of low-coordinated surface free atoms, and subsequent L10nucleation. The developed L10-Ga-PtNi/C catalysts display outstanding performance in H2–air fuel cells under both light- and heavy-duty vehicle conditions. Under the latter condition, the 40% L10-Pt50Ni35Ga15/C catalyst delivers a high current density of 1.67 A cm−2at 0.7 V and retains 80% of the current density after extended 90,000 cycles, which exceeds the United States Department of Energy performance metrics and represents among the best cathodic electrocatalysts for practical proton-exchange membrane fuel cells.

The unstable interface between lithium metal anodes and carbonate-based electrolytes is a key challenge limiting the cycling lifespan of high-energy lithium metal batteries. Here, a resilient artificial solid electrolyte interphase (RASEI) was designed by regulating poly(hexafluorobutyl acrylate) (PHFBA) matrix with the benzene-containing bisphenol A ethoxylate dimethacrylate (BAED) crosslinker to address this issue. The rigid BAED molecule can finely tune the flexible PHFBA matrix, enabling superior resilience from 600% elongation to 90% compression with a high Young’s modulus of over 2 MPa. RASEI with these characteristics can accommodate large volume changes of lithium metal and ensure the intimate contact between the lithium metal and the RASEI during battery operation. Consequently, it facilitated homogeneous lithium deposition while mitigating parasitic side reactions. Thanks to the tough and resilient nature of the fluorinated RASEI, the long-term cycling of Li∣∣Li symmetric cells can be achieved for over 500 h at 1 mA cm−2and 1 mAh cm−2. The following post-mortem of cycled Li metal reveals that Li dendrite growth is effectively inhibited. Furthermore, the NCM811 pouch cell with a high cathode loading of 20 mg cm−2exhibits a capacity retention of over 85% after 200 cycles at 1 C.

The optimal electrolyte for ultrahigh energy density (>400 Wh/kg) lithium-metal batteries with a LiNi0.8Co0.1Mn0.1O2cathode is required to withstand high voltage (≥4.7 V) and be adaptable over a wide temperature range. However, the battery performance is degraded by aggressive electrode–electrolyte reactions at high temperature and high voltage, while excessive growth of lithium dendrites usually occurs due to poor kinetics at low temperature. Accordingly, the development of electrolytes has encountered challenges in that there is almost no electrolyte simultaneously meeting the above requirements. Herein, a high chaos electrolyte design strategy is proposed, which promotes the formation of weak solvation structures involving multiple anions. By tailoring a Li+-EMC-DMC-DFOB–-PO2F2–-PF6–multiple-anion-rich solvation sheath, a robust inorganic-rich interphase is obtained for the electrode–electrolyte interphase (EEI), which is resistant to the intense interfacial reactions at high voltage (4.7 V) and high temperature (45 °C). In addition, the Li+solvation is weakened by the multiple-anion solvation structure, which is a benefit to Li+desolventization at low temperature (−30 °C), greatly improving the charge transfer kinetics and inhibiting the lithium dendrite growth. This work provides an innovative strategy to manipulate the high chaos electrolyte to further optimize solvation chemistry for high voltage and wide temperature applications.

Transition metal supported N-doped carbon (M-N-C) catalysts for oxygen reduction reaction (ORR) are viewed as the promising candidate to replace Pt-group metal (PGM) for proton exchange membrane fuel cells (PEMFCs). However, the stability of M-N-C is extremely challenging due to the demetalation, H2O2attack, etc. in the strongly oxidative conditions of PEMFCs. In this study, we demonstrate the universal effect of Zn on promoting the stability of atomically dispersed M-Nx/C (M = Co, Fe, Mn) catalysts and the enhancement mechanism is unveiled for the first time. The best-performing dual-metal-site Zn-Co-N-C catalyst exhibits a high half-wave potential (E1/2) value of 0.81 V vs.reversible hydrogen electrode (RHE) in acid and outstanding durability with no activity decay after 15,000 accelerated degradation test (ADT) cycles at 60 °C, surpassing most reported Co-based PGM-free catalysts in acid media. For comparison, the Co-N-C in the absence of Zn suffers from a rapid degradation after ADT due to the demetalation and higher H2O2yield. X-ray adsorption spectroscopy (XAS) and density functional theory (DFT) calculations suggest the more negative formation energy (by 1.2 eV) and increased charge transfer of Zn-Co dual-site structure compared to Co-N-C could strength the Co-N bonds against the demetalation and the optimized d-band center accounts for the improved ORR kinetics.

Aqueous zinc-ion batteries (AZIBs) are receiving widespread attention due to their abundant resources, low material cost, and high safety. However, the susceptibility of Zn metal anodes to corrosion and hydrogen evolution limits their further practical applications. Replacing Zn metal with intercalation-type anode material and constructing rocking-chair-type batteries could be an effective way to significantly prolong the cycle life of AZIBs. Herein, we present copper selenide with different crystal phase structures through a facile redox reaction as an anode for AZIBs. By comparing and analyzing different copper selenide phases, it is found that the cubic Cu2–xSe shows superior structural stability and highly reversible Zn2+storage. Theoretical calculation results further demonstrate that the cubic Cu2–xSe possesses an increased electrical conductivity, higher Zn2+adsorption energy, and reduced diffusion barrier, thereby promoting the storage reversibility and (de)intercalation kinetics of the Zn2+ion. Thus, the Cu2–xSe anode delivers a long-term service life of over 15 000 cycles and impressive cumulative capacity. Furthermore, the full-cells assembled with the MnO2/CNT cathode operate stably for over 1500 cycles at 6 mA cm–2at a negative/positive (N/P) capacity ratio of ∼1.53. This work provides a more ideal Zn-metal-free anode, which helps to push the practical applications of AZIBs.

NaClO4and NaPF6, the most universally adopted electrolyte salts in commercial sodium-ion batteries (SIBs), have a decisive influence on the interfacial chemistry, which is closely related to electrochemical performance. The complicated and ambiguous interior mechanism of microscopic interfacial chemistry has prevented reaching a consensus regarding the most suitable sodium salt for high-performance SIB electrolytes. Herein, we reveal that the solvation structure induced by different sodium salt anions determines the Na+desolvation kinetics and interfacial film evolution process. Specifically, the weak interaction between Na+and PF6–promoted sodium desolvation and storage kinetics. The solvation structure involving PF6–induced the anion’s preferential decomposition, generating a thin, inorganic compound–rich cathode–electrolyte interphase that ensured interface stability and inhibited solvent decomposition, thereby guaranteeing electrode stability and promoting the charge transfer kinetics. This study provides clear evidence that NaPF6is not only more compatible with industrial processes but also more conducive to battery performance. Commercial electrolyte design employing NaPF6will undoubtedly promote the industrialization of SIBs.

A new family of organosulfur polymer cathodes were developed to completely suppress the generation and dissolution of the high-order LiPSs and work under the solid–solid conversion mechanism. The designed cathode demonstrates outstanding electrochemical behaviors in carbonate electrolyte: a high capacity of 530 mA h g−1after 1000 cycles at 1 C, when the sulfur loading further increased to around 4.5 mg cm−2, there is no obvious capacity fading in pouch cell even after 125 cycles at 0.2 C.

Thin lithium (Li) metal foils have been proved to be indispensable yet elusive for practical high-energy-density lithium batteries. Currently, the realization of such thin foils (<50 μm) is impeded by the inferior mechanical processability of metallic Li. In this work, we demonstrate that the combination of solid solution strengthening and second phase strengthening, achieved by the addition of silver fluoride (AgF) to Li metal, can substantially enhance both the strength and ductility of metallic Li. Benefiting from the improved machinability, we succeed in fabricating an ultrathin (down to 5 μm), freestanding, and mechanically robust Li-AgF composite foil. More interestingly, the in situ-formed LixAg-LiF skeleton in the composite facilitates Li diffusion kinetics and uniform Li deposition, where the thin Li-AgF electrode displays a prolonged cycle life over 500 h at 1 mA cm–2and 1 mAh cm–2in a carbonate electrolyte. Coupled with a commercial LiCoO2cathode (3.4 mAh cm–2), the LiCoO2||Li-AgF cell delivers a notable capacity retention of ∼90% over 100 cycles at 0.5 C with a low negative/positive ratio of 2.5.

The “solvent-in-salt” electrolytes for an aqueous system, including “water-in-salt” electrolytes and “bisolvent-in-salt” electrolytes, have shown significantly improved electrochemical stability toward low-voltage anodes and high-voltage cathodes. However, the heavy use of salt raises concerns of high cost, high viscosity, inferior wettability, and poor low-temperature performance. Herein, a “localized bisolvent-in-salt electrolyte” is proposed by introducing 1,1,2,2-tetrafluoroethyl-2,2,3,3-tetrafluoropropyl ether (TTE) as the diluent to the high-concentration water/sulfolane hybrid (BSiS-SL) electrolytes, forming a ternary solvent-based electrolyte, Li(H2O)0.9SL1.3·TTE1.3(HS-TTE). The introduction of TTE dilutes the compact ionic clusters, while the original primary Li+solvation structure remains, and in the meantime, boosts the formation of a robust solid electrolyte interphase. As a result, a wide electrochemically stable window of 4.4 V is achieved. In comparison with the bisolvent BSiS-SL system, the trisolvent HS-TTE electrolyte exhibits a low salt concentration of 2.1 mol kg–1, resulting in drastically reduced viscosity, superb separator wettability, and largely improved low-temperature performance. The constructed 2.5 V Li4Ti5O12/LiMn2O4cell shows an excellent capacity retention of 80.7% after 800 cycles, and the cell can even work at −30 °C. With these extraordinary advantages, the fundamental designing strategy of the HS-TTE electrolyte developed in this work can promote the practical applications of solvent-in-salt electrolytes.

High-entropy ceramics (HECs) have gained great attention as one of the rapidly growing families of high-entropy materials. Increasing the species yields enhanced properties owing to high configurational entropy and elemental synergies, alluding to the potential of HECs in designing materials with tailored properties. However, the question is obscure as to whether the multiple elements show priority in the arrangement in the structure, as well as how they regulate the bond length. Here, we synthesize a medium-entropy garnet-structured electrolyte Li6La3Zr0.5Hf0.5Ta0.5Nb0.5O12(ME-LLZO) and elucidate its short-range structure based on the calculated supercell and neutron pair distribution function (PDF) refinement. Extended bottleneck size, elongated Li–O bond length, and local clustering of 16asites, where tetravalent ions prefer to be the first-nearest octahedrons of pentavalent ions, are observed. Differences between the multiple cations inevitably influence the short-range structure, and our study provides a new paradigm for future exploration of HEC-based solid-state electrolytes.

The uneven distribution of state of charge (SoC) in the lithium-ion battery is a key factor to cause fast decay of local electrochemical performance. Here, we report an acoustic method to realize SoC mapping in a pouch cell. A focused ultrasound beam is used to scan the cell, and the transmitted ultrasonic wave is analyzed with a deep learning algorithm based on the feedforward neural network. The deep learning algorithm effectively suppresses the disturbance of structural variation in different cells. As a result, the root mean squared error (RMSE) of the estimated local SoC is reduced to 3.02% when applying to different positions on different pouch cells, which is 11.07% of the RMSE by direct fitting SoC with acoustic time of flight. Combining with the progressive scanning technique, our method can realize non-destructive in situSoC mapping with 1 mm in-plane resolution on pouch cells.

Solid polymer electrolytes suffer from the low ionic conductivity and poor capability of suppressing lithium dendrites, which have greatly hindered the practical application of solid-state lithium-metal batteries. Here, we report a novel laponite sheet (LS) with a large negatively charged surface as an additive in a solid composite electrolyte (poly(ethylene oxide)-LS) to rearrange the lithium-ion environment and enhance the mechanical strength of the electrolytes (PEO-LS). The strong electrostatic regulation of laponite sheets assists the dissociation of lithium bis(trifluoromethanesulfonyl)imide (LiTFSI) and constructs multiple transport channels for free lithium ions, achieving a high ionic conductivity of 1.1 × 10–3S cm–1at 60 °C. Furthermore, LS facilitates the in situ formation of a LiF-rich interface because of the boosting TFSI–anion concentration, which significantly suppresses lithium dendrites and prevents short circuit. As a result, the assembled LiFePO4|PEO-LS|Li battery demonstrates a long cycle life of over 800 cycles and a high Coulombic efficiency of 99.9% at 1C and 60 °C. When paired with a high-voltage NCM811 cathode, the battery also demonstrates excellent cycling stability and rate capability.

Gd-gradient doping improves oxygen framework stability and suppress unfavorable phase transition of LiCoO2at 4.6 V. Accordingly, the modified LiCoO2achieves excellent capacity retention of 91.2% over 200 cycles.

The Qinghai-Tibet Railway has been operating safely for 16 years in the permafrost zone and the railroad subgrade is generally stable by adopting the cooling roadbed techniques. However, settlement caused by the degradation of subgrade permafrost in the embankment-bridge transition sections (EBTS) is one of the most representative and severe distresses. A field survey on 440 bridges (including 880 EBTSs) was carried out employing terrestrial laser scanning and ground-penetrating radar for comprehensively assessing all EBTSs in the permafrost zone. The results show that the types of distresses of EBTSs were differential settlement, upheaval mounds of the protection-cone slopes, subsidence of the protection-cone slopes, surface cracks of the protection cones and longitudinal and transverse dislocation of the wing walls. The occurrence rates of these distresses were 78.93, 3.47, 11.56, 3.36, 21.18 and 4.56%, respectively. The most serious problem was differential settlement, and the average differential settlement amount (ADSA) was 15.3 cm. Furthermore, the relationships between differential settlement and 11 influencing factors were examined. The results indicate that ADSA is greater on the northern side of a bridge than on the southern side and on the sunny slope than on the shady slope. It is also greater in the high-temperature permafrost region than in the low-temperature permafrost region and in the high-ice content area than in the low-ice content area. The EBTSs are more influenced by ice content than by ground temperature. The ADSA increases when the embankment height increases, the particle size of subgrade soil decreases and the surface vegetation cover decreases.

Aqueous zinc–sulfur (Zn–S) batteries are regarded as excellent candidates for energy storage applications due to their low cost, non-toxicity, and high theoretical energy density. However, the low utilization of the traditional thick foil-type Zn anode would severely restrict the overall energy density of Zn–S batteries. Herein, a mechanically and chemically stable powder-Zn/indium (pZn/In) anode with finite Zn loading was designed and constructed for enhancing the cycle stability of aqueous Zn–S batteries. Notably, the bifunctional In protective layer can inhibit the corrosion rate of highly active pZn and homogenize the Zn2+flux during Zn plating/stripping. As a result, the obtained pZn/In anode exhibits a greatly improved cyclability of over 285 h even under a much harsh test condition (10 mA cm−2, 2.5 mA h cm−2, Zn utilization rate: ∼38.5%). Furthermore, when assembled with an S-based cathode at a negative/positive (N/P) capacity ratio ∼2, the full cell delivers a high initial specific capacity of ∼803 mA h g−1and operates stably for over 300 cycles at 2C with a low capacity fading rate of ∼0.17% per cycle.

Widespread deployment of Small Satellite Networks (SSN) fosters the foreseen integration of space-air-ground networks to provide worldwide Internet access to oceanic and remote airspace. However, the dynamic topology of SSN, the lossy wireless link, and the limited transmission resources induce unprecedented challenges to Deterministic Satellite Network Transmission (DSNT) for the sake of improving the utility of the SSN facility. Motivated by these challenges, this work aims to develop a Deterministic Satellite Network Transmission approach with deterministic Spatio-temporal routing, Redundant coding and Multipath scheduling (DSNT-SRM) for bolstering superior communications of SSN. DSNT-SRM uses the ephemeris information and dynamic resource update mechanism to predict all upcoming communication opportunities and construct the deterministic spatio-temporal routing paths. By combining sparse and redundant network coding mechanisms, DSNT-SRM no longer cares about the arrival of each packet, but the number of coded packets it receives, since the lost packets can be compensated with deterministic redundant traffic. Moreover, the adaptive traffic balance between multiple spatio-temporal paths is designed to provide a deterministic delay guarantee when facing limited node resources and multi-user competition. Extensive experiments show that DSNT-SRM can achieve satisfactory performance improvement in reducing delay and improving delivery rate.

Ni-rich LiNixCoyMnzO2(NCMxyz, x + y + z = 1, x ≥ 0.8) layered oxide materials are considered the main cathode materials for high-energy-density Li-ion batteries. However, the endless cracking of polycrystalline NCM materials caused by stress accelerates the loss of active materials and electrolyte decomposition, limiting the cycle life. Hence, understanding the chemo-mechanical evolution during (de)lithiation of NCM materials is crucial to performance improvement. In this work, an optical fiber with με resolution is designed to in operandodetect the stress evolution of a polycrystalline LiNi0.8Co0.1Mn0.1O2(P-NCM811) cathode during cycling. By integrating the sensor inside the cathode, the stress variation of P-NCM811 is completely transferred to the optical fiber. We find that the anisotropy of primary particles leads to the appearance of structural stress, inducing the formation of microcracks in polycrystalline particles, which is the main reason for capacity decay. The isotropy of primary particles reduces the structural stress of polycrystalline particles, eliminating the generation of microcracks. Accordingly, the P-NCM811 with an ordered arrangement structure delivered high electrochemical performance with capacity retention of 82% over 500 cycles. This work provides a brand-new perspective with regard to understanding the operandochemo-mechanical evolution of NCM materials during battery operation, and guides the design of electrode materials for rechargeable batteries.This work highlights the grain orientation effect on the structural stress evolution of LiNi0.8Co0.1Mn0.1O2cathodes via operandooptical fiber monitoring, furthering our understanding of the operandochemo-mechanical evolution of NCM materials.

Lithium (Li) metal anodes have the potential to stimulate the development of secondary batteries due to their high theoretical specific capacities and low redox potentials among all possible solid secondary anode compounds. However, the growth of Li dendrites during repeated Li stripping/plating processes leads to low coulombic efficiencies (CEs) and safety hazards, which significantly hinders their practical application. In this work, commercial Cu foil was modified in situby Cu3N nanowires (Cu3N NWs/Cu) and used as the current collector for a Li anode. In addition to decreasing the true current density of the anode and alleviating the volume change during the cycles, Cu3N reacted with Li during the initial cycle (3Li + Cu3N → Li3N + 3Cu), which enabled the formation of a Li3N-rich solid electrolyte interphase (SEI). This Li3N-rich SEI with a high ionic conductivity not only boosted Li ion transport but also promoted the homogeneous deposition of Li viaincreased Li nucleation sites. The improvements in both mass transport and deposition dynamics restrained dendrite growth. As a result, the Cu3N NWs/Cu anode had stable Li plating/stripping over 270 cycles with a high average CE of 98.6% at 1 mA cm−2, with Li capacities of 1 mA h cm−2. A long cycling lifespan of 430 cycles was achieved using a full cell with a high-load LiFePO4cathode (mass loading: 10 mg cm−2) and a Cu3N NWs/Cu-Li anode (N/P= 2.35), demonstrating the effectiveness and practicality of the Cu3N NWs/Cu current collector in stabilizing the Li anode.

LiI is proposed as a bifunctional additive to increase the ionic conductivity of PEO electrolytes and to construct a stable Li/PEO interphase, enabling outstanding electrochemical performances for solid-state Li-metal batteries with LiFePO4and LiNi0.8Mn0.1Co0.1O2cathodes.

Graphical Abstract: Thermal safety analysis helps us gain a deep understanding of the causes of LIB safety issues. Monitoring and thermal management prevent and alert potential safety accidents. Intelligent fire-fighting system effectively extinguishes LIB fires that have already occurred. This review proposes a complete set of solutions for the thermal safety of LIBs.

This review systematically compares the different effects of O2-type and O3-type structures on voltage decay for Li-rich layered oxide (LRLO) cathode.The development of O2-type materials and the corresponding mechanisms for addressing voltage decay are comprehensively reviewed.The perspectives and challenges for designing high-performance O2-type LRLO cathodes without voltage decay are proposed.

In an integrated hydrogen energy utilization system, the hydrogen storage device needs to meet hydrogen supplies and demands of different pressure levels, traditional hydrogen storage systems will lead to more energy consumption and lower hydrogen supply efficiency. To address this problem, a cascade hydrogen storage system (CHSS) is proposed in this study. By configuring three hydrogen storage tanks (HSTs) with three pressure levels, the CHSS is capable of serving hydrogen for fuel cell supply, long-term storage, and refueling stations. The corresponding control strategy of hydrogen flow between HSTs is proposed. It shows that an optimal capacity configuration scheme with pressures of 3 MPa, 24.44 MPa, and 45 MPa and a hydrogen storage capacity of 401.7 kg, optimized by NSGA-II, can meet the stable operation of the system. Comparative studies show that the proposed CHSS configuration can reduce the cost by about 3.78 %, the energy consumption by about 6.92 %, and the hydrogen supply loss rate by about 12 % compared to the existing solutions under the tested conditions.

The development of lithium-ion batteries (LIBs) possessing excellent fast charging performance is particularly important for expanding the worldwide application market of LIBs. However, the grievous growth of lithium dendrites during high rate charging and discharging process occurring on the surface of the anode material still restricts the development of commercial fast charging LIBs, which raises capacity deterioration and even enormous safety risks. Herein, we developed simple physical mixing of active carbon (AC) powder into graphite negative slurry to generate the hybrid fast charging anode (called AS anode), which can realize unprecedented fast charging capability whether at room temperature or low temperature, along with greatly improved capacity retention cycling at high 2 C rate. Importantly, the density functional theory calculation and combined characterizations including in situ electrochemical confocal system spectroscopy and lithium ion (Li+) diffusion coefficient analysis can decipher that AC particles with rapid Li+diffusion and adsorption can act as ion transport islands in graphite electrode to accelerate the transport process of lithium ion inside the whole negative electrode, leading to the faster charging performance. This work not only promotes the development of anode construction with fast charging capability for LIBs, but also deciphers the ion transport mechanism inside the electrode.

The formation of cathode-electrolyte interphase (CEI) is closely related to the solvation structure in direct contact with the cathode. The de-solvated solvent molecules are subject to the attack of highly catalytic transition metal ions in the cathode materials (such as Ni-rich LiNi0.8Co0.1Mn0.1O2, Ni-rich NCM), especially at high voltage or high temperature, leading to the poor CEI structure that accelerates the deterioration of rechargeable batteries. Considerable strategies have been proposed to solve this issue. Herein, we have constructed a porous Mg-MOF buffer layer on the surface of Ni-rich NCM, which not only greatly reduces the contact between solvent molecules and cathodes to alleviate the extensive interface reactions, but also promote the de-solvation of Li+solvation structure through strong affinity between solvents and Mg2+. The partially de-solvated structure induces the anion to participate in the solvation structure and contributes to the formation of a uniform LiF-rich CEI with superior mechanical integrity and chemical stability. Therefore, the NCM with Mg-MOF buffer layer exhibits improved cycling stability at both elevated temperature of 45 °C and high voltage of 4.5 V with lithium as anode. Moreover, the modified NCM/graphite full cells also deliver ultra-stable rechargeable capability with a remarkable capacity retention of 87.3% over 1000 cycles as compared to the only 21.7% of pristine NCM based cells.

The leakage of flammable and explosive lithium-ion battery (LIB) electrolytes can be one of the early symptoms of battery malfunction and can even lead to spontaneous battery combustion or electric car explosion. Therefore, it is necessary to find a rapid and simple method to monitor any leakage of LIB electrolytes. However, LIB electrolytes are generally composed of volatile and redox neutral carbonate solvents. Trace amounts of electrolyte leakage are difficult to detect effectively and rapidly by existing compact sensors. Here, for the first time, we propose a strategy that cooperatively combines the sensitivity of organic field-effect transistors (OFETs) and the selectivity of biurea receptors to detect LIB electrolyte leakage. The fabricated sensors show much higher sensitivity than the pristine sensor without receptors, and the detection limit of the sensor toward diethyl carbonate was 1.4 ppm. Trace amounts of LIB electrolyte leakage could be detected effectively in seconds, with 200 nL electrolyte leakage leading to a 3% response. We also demonstrate the real-time detection of LIB electrolyte leakage by our OFET sensors. The excellent performance of the receptor-coated OFET sensor makes it a good candidate for LIB safety monitoring and provides a promising platform for the development of sensing technologies.

“Water-in-salt” electrolytes have significantly expanded the electrochemical stability window of the aqueous electrolytes from 1.23 to 3 V, making highly safe 3.0 V aqueous Li-ion batteries possible. However, the awkward cathodic limit located at 1.9 V (versus Li+/Li) and the high cost of the expensive salts hinder the practical applications. In this work, an ideal “bisolvent-in-salt” electrolyte is reported to tune the electrolyte solvation structure via introducing sulfolane as the co-solvent, which significantly enhances the cathodic limit of water to 1.0 V (versus Li+/Li) at a significantly reduced salt concentration of 5.7 mol kg–1. Due to the competitive coordination of sulfolane, water molecules that should be in the primary solvation sheath of Li+are partly substituted by the electrochemically stable sulfolane, significantly decreasing the hydrogen evolution. Meanwhile, the unique electrolyte structures enable the formation and stabilization of a robust solid electrolyte interphase. As a result, a 2.4 V LiMn2O4/Li4Ti5O12full cell with a high energy density of 128 Wh kg–1is realized. The hybrid water/sulfolane electrolytes provide a brand new strategy for designing aqueous electrolytes with an expanded electrochemical stability window at a low salt concentration.

The linear and crosslink types of PPH provide different topological structures, in which the linear type shows much higher Li transfer and storage.

With the fast development of large-scale energy storage, aqueous Zn-based rechargeable batteries have attracted more and more attention because of their high-level safety, low cost, and environmental friendliness. The Zn metal anode is fascinating for aqueous Zn-based rechargeable batteries due to its high volume-specific capacity (5855 mA h cm–3), low negative potential (−0.762 V vs standard hydrogen electrode), and abundant resources. However, the practical application of the Zn metal anode is hindered by the challenge of serious dendrite growth. To address this, herein, we report a highly reversible and anticorrosive Zn anode enabled by a Ag nanowires (AgNWs) layer. By effectively lowering the nucleation overpotential and providing a high specific surface area to construct abundant sites inducing Zn uniform deposition, the designed Zn-AgNWs anode could ensure dendrite-free deposition to improve the reversibility (600 h at 2 mA h cm–2). During cycling, Zn deposition on the AgNWs surface drives the in situ formation of the AgZn3alloy to constitute a natural protective layer, which can prevent the direct corrosion reaction between Zn and the electrolyte. Thus, the Zn-AgNWs|MnO2full cell exhibits excellent electrochemical performance with large specific capacity and outstanding rate capability and retains a high capacity retention at 0.6 A g–1even after 800 cycles.

Aqueous zinc ion batteries (ZIBs) are emerging as a promising candidate in the post-lithium ion battery era, while the limited choice of cathode materials plagues their further development, especially the tunnel-type cathode materials with high electrochemical performance. Here, a tunnel-type vanadium-based compound based on hydrogen vanadium bronze (HxV2O5) microspheres has been fabricated and employed as the cathode for fast Zn2+ions’ intercalation/deintercalation, which delivers an excellent capacity (425 mAh g–1at 0.1 A g–1), a remarkable cyclability (91.3% after 5000 cycles at 20 A g–1), and a sufficient energy density (311.5 Wh kg–1). As revealed by the experimental and theoretical results, such excellent electrochemical performance is confirmed to result from the fast ions/electrons diffusion kinetics promoted by the unique tunnel structure (3.7 × 4.22 Å2, along the cdirection), which accomplishes a low Zn2+ion diffusion barrier and the superior electron-transfer capability of HxV2O5. These results shed light on designing tunnel-type vanadium-based compounds to boost the prosperous development of Zn2+ion storage cathodes.

Because of its high energy density and low cost, the room-temperature sodium–sulfur (RT Na–S) battery is a promising candidate to power the next-generation large-scale energy storage system. However, its practical utilization is hampered by the short life span owing to the severe shuttle effect, which originates from the “solid–liquid–solid” reaction mechanism of the sulfur cathode. In this work, fluoroethylene carbonate is proposed as an additive, and tetraethylene glycol dimethyl ether is used as the base solvent. For the sulfurized polyacrylonitrile cathode, a robust F-containing cathode–electrolyte interphase (CEI) forms on the cathode surface during the initial discharging. The CEI prohibits the dissolution and diffusion of the soluble intermediate products, realizing a “solid–solid” reaction process. The RT Na–S cell exhibits a stable cycling performance: a capacity of 587 mA h g–1is retained after 200 cycles at 0.2 A g–1with nearly 100% Coulombic efficiency.

This paper investigates the impact of phase-locked loop (PLL) dynamic on the stability of DC-link voltage control (DVC) in voltage source converter (VSC) attached to weak grid. To start with, a small signal model of VSC attached to weak grid in DVC timescale is presented for stability analysis. On the basis, the dynamic characteristics of VSC are analyzed from the perspective of damping and restoring components which can determine the stability. With considering PLL dynamic, it is found that PLL performs as a phase-lag regulation for DVC and generates additional negative damping component in weak grid, thus weakening the stability of VSC. Furthermore, impacts of PLL’s phase-lag characteristics on additional damping and restoring coefficients are evaluated with variation of grid strengths, operating points and PLL bandwidths to reveal the impact mechanism of PLL dynamic on stability of DVC in VSC. Finally, time-domain simulation and StarSim hardware-in-the-loop (HIL) experimental results are conducted to validate the aforesaid stability analysis.

Tungsten carbide (W2C) has emerged as a potential alternative to noble-metal catalysts toward hydrogen evolution reaction (HER) owing to its Pt-like electronic configuration. However, unsatisfactory activity, dilatory electron transfer, and inefficient synthesizing methods, especially for nanoscale particles, have severely hindered its large-scale applications. Herein, a novel heterostructure composed of W2C and tungsten phosphide (WP) embedded in nitrogen-decorated carbon (W2C/WP@NC) was constructed as an efficient HER electrocatalyst. The as-prepared W2C/WP@NC catalyst exhibits remarkable electrocatalytic activity and robust durability toward HER both in acids and bases. More notably, the W2C/WP@NC catalyst demonstrates low overpotentials of 116.37 and 196.2 mV to afford a current density of 10 mA cm–2and reveals slight potential decays of about 6.4 and 7.64% over 12 h continuous operation in bases and acids, respectively. The overall water-splitting performance was further evaluated using the W2C/WP@NC catalyst as the cathode and commercial RuO2as the anode in an electrolyzer, which can realize an overall current density of 10 mA cm–2and maintain long durability of more than 12 h with a small cell voltage of 1.723 V. This work opens up new opportunities for exploring cost-efficient electrocatalysts in sustainable energy conversion.

Rare-earth (RE) solid-state halide electrolytes have been extensively studied recently in the field of lithium (Li) ion all-solid-state batteries (ASSBs) due to their excellent electrochemical performances. Herein, a new RE-based solid halide electrolyte Li3HoBr6(LHB) has been synthesized and exhibits high Li ion conductivity up to mS cm–1at room temperature. Theoretical calculations have identified four different Li ion migration pathways, in which the out-of-plane pathways are much more favorable than the direct in-plane pathways. In addition, LHB has a wider electrochemical window in comparison to a sulfide solid electrolyte and good deformability. The LHB-based Li-sulfur ASSB assembled by cold pressing can exhibit good cycling stability with high Coulombic efficiency, which shows that LHB has potential application in ASSBs.

Lithium-sulfur (Li−S) batteries are regarded as one of the most promising next-generation energy storage systems due to their high theoretical energy density and low material cost. However, the conventional ether-based electrolytes of Li−S batteries are extremely flammable and have high solubility of lithium polysulfides (LiPS), resulting in a high safety risk and a poor life cycle. Herein, we report an ether/carbonate co-solvent fluorinated electrolyte with a special solvation sheath of Li+, which can prevent the formation of dissoluble long-chain LiPS of the sulfur cathode, restrict Li dendrite growth at the anode side, and show fire resistance in combustion experiments. As a result, the proposed Li−S batteries with 70 wt% sulfur content in its cathode deliver stable life cycle, low self-discharge ratio, and intrinsic safety. Therefore, the unique passivation characteristics of the designed fluorinated electrolyte break several critical limitations of the traditional “liquid phase”-based Li−S batteries, offering a facile and promising way to develop long-life and high-safety Li−S batteries.

Aqueous zinc-ion batteries (ZIBs) with cost-effective and safe features are highly competitive in grid energy storage applications, but plagued by the sluggish Zn2+diffusion kinetics and poor cyclability of cathodes. Herein, a one-stone-two-birds strategy of La3+incorporation (La–V2O5) is developed to motivate Zn2+insertion/extraction kinetics and stabilize vanadium species for V2O5. Theoretical and experimental studies reveal the incorporated La3+ions in V2O5can not only serve as pillars to expand the interlayer distance (11.77 Å) and lower the Zn2+migration energy barrier (0.82 eV) but also offer intermediated level and narrower band gap (0.54 eV), thus accelerating the electron/ion diffusion kinetics. Importantly, the steadily doped La3+ions effectively stabilize the V–O bonds by shortening the bond length, thereby inhibiting vanadium species dissolution. Therefore, the resulting La–V2O5-ZIBs deliver an exceptional rate capacity of 405 mA h g–1(0.1 A g–1), long-term stability with 93.8% retention after 5000 cycles (10 A g–1), and extraordinary energy density of 289.3 W h kg–1, outperforming various metal-ions-doped V2O5cathodes. Moreover, the La–V2O5pouch cell presents excellent electrochemical performance and impressive flexibility and integration ability. The strategies of incorporating rare-earth-metal ions provide guidance to other well-established aqueous ZIBs cathodes and other advanced electrochemical devices.

Lithium loss during the initial charge process inevitably reduces the capacity and energy density of lithium-ion batteries. Cathode additives are favored with respect to their controllable prelithiation degree and scalable application; however, the insulating nature of their delithiation products retards electrode reaction kinetics in subsequent cycles. Herein, we propose a prelithiation separator by modifying a commercial separator with a Li2S/Co nanocomposite to compensate for the initial capacity loss. The Li2S/Co coating layer extracts active lithium ion during the charge process and shows a delithiation capacity of 993 mA h g–1. When paired with a LiFePO4|graphite full cell, the reversible capacity is increased from 112.6 to 150.3 mA h g–1, leading to a 29.5% boost in the energy density. The as-prepared pouch cell also demonstrates a stable cycling performance. The excellent electrochemical performance and the scalable production of the prelithiation separator reveal its great potential in lithium-ion battery industry application.

Solid-state lithium metal batteries (SSLMBs), using lithium metal as the anode and garnet-structured Li6.5La3Zr1.5Ta0.5O12(LLZTO) as the electrolyte, are attractive and promising due to their high energy density and safety. However, the interface contact between the lithium metal and LLZTO is a major obstacle to the performance of SSLMBs. Here, we successfully improve the interface wettability by introducing one-dimensional (1D) TiO2nanofibers into the lithium metal to obtain a Li-lithiated TiO2composite anode (Li–TiO2). When 10 wt % TiO2nanofibers are added, the formed composite anode offers a seamless interface contact with LLZTO and enables an interfacial resistance of 27 Ω cm2, which is much smaller than 374 Ω cm2of pristine lithium metal. Due to the enhanced interface wettability, the symmetric Li–TiO2|LLZTO|Li–TiO2cell upgrades the critical current density to 2.2 mA cm–2and endures stable cycling over 550 h. Furthermore, by coupling the Li–TiO2composite anode with the LiFePO4cathode, the full cell shows stable cycling performance. This work proves the role of TiO2nanofibers in enhancing the interface contact between the garnet electrolyte and the lithium metal anode and improving the performance of SSLMBs and provides an effective approach with 1D additives for solving the interface issues.

Though low-cost and environmentally friendly, Li–Mn–O cathodes suffer from low energy density. Although synthesized Li4Mn5O12-like overlithiated spinel cathode with reversible hybrid anion- and cation-redox (HACR) activities has a high initial capacity, it degrades rapidly due to oxygen loss and side-reaction-induced electrolyte decomposition. Herein, we develop a two-step heat treatment to promote local decomposition as Li4Mn5O12→ 2LiMn2O4+ Li2MnO3+ 1/2 O2↑, which releases near-surface reactive oxygen that is harmful to cycling stability. The produced nanocomposite delivers a high discharge capacity of 225 mAh/g and energy density of over 700 Wh/kg at active-material level at a current density of 100 mA/g between 1.8 to 4.7 V. Benefiting from suppressed oxygen loss and side reactions, 80% capacity retention is achieved after 214 cycles in half cells. With industrially acceptable electrolyte amount (6 g/Ah), full cells paired with Li4Ti5O12anode have a good retention over 100 cycles.

Nickel-rich Li(NixCoyMn1–x–yO2) (x≥ 0.6) is considered to be a predominant cathode for next-generation lithium-ion batteries (LIBs) due to its towering specific energy density. Unfortunately, serious structural degradation causes rapid capacity degradation with the increase in nickel content. Herein, a Co and Ti co-modified LiNi0.8Co0.1Mn0.1O2(NCM-811) cathode ameliorates the reversible capacity together with the rate capability by obviously alleviating the lattice structure degradation and microscopic intergranular cracks. Further studies show that the titanium doping effectively reduces the cation mixing and also stabilizes the crystal structure, while the spinel phase formed at the surface by a cobalt oxide coating is much stable than the layered phase at high voltage, which can alleviate the generation of micro-cracks. After 0.5% Co oxide coating and 1% Ti doping (T1Co0.5-NCM), a superior rate capability (121.75 mA h g–1at 20 C between 2.7 and 4.5 V) and predominant capacity retention (74.2%) are observed compared with the pristine NCM-811 (59.5%) after 400 cycles between 2.7 and 4.7 V. This work supplies an eminent design of high-voltage and high-rate layered cathode materials and has a huge application prospect in the next generation of high-energy LIBs.

A highly sensitive and selective electrochemical chiral sensor was developed based on the competitive supramolecular interaction of carbon nanofibers (CNFs) embedded sulfobutyl ether-β-cyclodextrin (SBE-β-CD) with optically active cationic drugs at glassy carbon electrode (GCE). The difference in intermolecular hydrogen bonding/stability constant/enantioselectivity coefficient and Gibbs free energy of anionic host SBE-β-CD with enantiomers of amlodipine (R-/S-AML), clenbuterol (R-/S-CBL) and metoprolol (R-/S-MET) as a guest paved the way for efficient discrimination. The proposed sensing platform (CNFs-SBE-β-CD/GCE) could recognize the aforementioned enantiomers based on the discernible difference of peak potential (S/R-AML (ΔEp = 135 mV), R/S-MET (ΔEp = 99 mV) and R/S-CBL (ΔEp = 111 mV). The binding mechanisms and thermodynamic study of the enantiospecific behavior have been investigated using the host-guest chemistry approach inside the nanocavity and results suggest that S-AML, R-MET, and R-CBL show stronger stability constants than their antipodes. Formation of the diastereomeric complex was taken as a measure of enantioselectivity and experimental results indicated that anionic SBE-β-CD is a better chiral ligand than neutral cyclodextrins. The fabricated sensor could be a useful low-cost electrochemical tool for molecular recognition of a variety of cationic species not only of drugs but also from other sources.